We've had the set for several years. The problem began about three or four months ago.
The only device connected is a Roku box, which is connected with an HDMI cable. However, the purple screen issue began before we used the Roku box. At that time, we had a cable box connected.
When the problem is occurring, pressing MENU does not show anything. Nothing is visible except the purple screen.
Knowing what is causing the problem and cost to repair would let me determine whether I would be able to repair it myself or not. I'm not opposed to fixing it myself if I can.
And thank you for your quick responses!
Thank you Aric. I appreciate your help and quick responses.